Menu Close

When was human dna discovered ?

DNA was discovered in 1869 by Swiss researcher Friedrich Miescher, who was initially trying to study the composition of lymphoid cells (white blood cells). The molecule is made from double-stranded deoxyribonucleic acid (deoxyribonucleosides) which are used by most viruses and bacteria to make viral proteins (called antigens), and also for making tiny pieces of DNA called primers (called “guide sequences”).

The whole DNA sequence of human also known as Human Genome Sequence (DISCOVERY GENOMICS). In order to identify the sequence of the first two bases on both sides of a single molecule, a chain of them must be present by mistake, although this has never been observed for any other molecule. Therefore, in 1869 when researchers determined that a double-stranded molecule of deoxyribonucleic acid (DNA) had indeed been found, they were unable to determine what kind of molecule it was. 

To put it simply: no one could tell how long it was nor how abundant it was in nature. This then led to the discovery of protein-DNA hybrids—bodies that contain fragments of DNA mixed with another molecule of the same type (called complementary or hybrid), also known as chimeric RNA and DNA-RNA hybrids. This discovery, like all the others, opened up new possibilities for scientists, enabling them to delve into genes to find new species, new diseases, and new techniques to analyze biological molecules. It was also at this moment that the term DNA technology was born, the use of the molecular structure of DNA and its base pairs for identifying sequences of nucleotides that would later go on to become ubiquitous in the field of biology and genetics, including for genetic engineering.

This process was so rapid, that some early biologists were able to identify an entire family of genes, including those of many that encode enzymes, hormones, neurotransmitters, etcetera, by following the technique pioneered by Francis Galton. Among other things, he used the name “gene” to describe the gene-mapping efforts. And today, thanks to the information provided by these maps (called genome data sets or genealogies) we know a lot about almost every organism on earth, including nearly everything from insects to birds, reptiles to mammals and even the plant kingdom. For example, the human genome contains more than 300 million genes, while the second largest chromosome (the first being the chimpanzee genome) represents only about 5,500 genes.

 These numbers might seem very large, but in reality they can be reduced to the number of nucleotides (from one side of our DNA) – in fact, the average area covered by one gene, roughly 2mm. We are therefore now able to identify more and more genes, and thus make much better tools for understanding human biology. Yet, this does not stop us from continuing the research of discovering genes, their structures (called gene architectures) and how they interact to create life. This continues over the course of history of our species. Although we are still at such a small scale we are beginning to see changes in genes and gene mutations that are taking place and that will fundamentally change our world. With advances in DNA-based technologies, we have even started to detect the existence of genes that control metabolism, hormones, immune systems, and so forth. 

As we continue to uncover the secrets of the universe, new areas of scientific inquiry arise and new forms of knowledge continue to emerge.

The key question, therefore, remaining remains: how did we get here? Are living beings as complex as they are supposed to be, if we do not yet know the answer to this question, how did we come to be the way we are, because we just didn’t make it as complex as possible? Or are there some forces operating that cannot be explained, to explain why such forces exist, why we feel compelled to act upon them, why we are as complex as we are? I think that the answers to the questions that I have outlined above cannot yet be guessed, and in any case are unknown. However, I believe that the key to gaining both understanding and insight into these questions lies in unearthing these mysteries. 

By finding answers that elude us right now, as well as in the future, we have begun to forge ahead toward answering all of the difficult questions that surround us. Let me share with you three instances where we began searching for answers in our quest for the ultimate mystery we seek…

1.) A Brief History of Molecular Biology (1870s-1890s)-

In 1870, a Swiss chemist named Franz Anton Kuhn created a method for making DNA that was described in his pioneering book Geschichten der Physikalisch-Chemische Gesellschaft. In this book Kuhn used the results of several experiments carried out in the laboratory to create the rudimentary version of our first, experimental map of the human genome. Through this experiment Kuhn used animals and plants, with varying levels of variation from species to species, to analyze DNA sequences and identify the different types of bases used. Within a year, he published his findings, and in 1873, Kuhn published his landmark theory of the DNA molecule. A year later, in 1874, Friedrich Herschel, also known as the discoverer of radiometric astronomy, conducted similar studies with a great deal more success, using animal DNA to map the evolution of gene sequences. He was inspired by Kuhn’s findings, and began working on a comprehensive project called karyotype theory. While still in laboratorywork, in 1874, James Watson, another British scientist, joined Kuhn in discovering the structure of DNA and proved that this structure was based on simple bonds between complementary bases – called deoxyribonucleoside triphosphate. Over the next couple of decades, until today, we know that DNA consists of single strand strands and double-stranded strands—with each string composed of complementary bases, termed A, C, G, and T, respectively—that fuse together to form different types of sequences, often with different lengths.

 Today, we know that these molecules are primarily responsible for how genes are expressed and their functions, but of course we know that their structures can be changed through mutation, deletion, insertion, addition, and recombination events. To date, we know that we know the exact structures of the nucleotides of genes through these processes, in addition to knowing their function. 

Though this is extremely important in terms of our ability to understand their interactions, for instance, in the expression of specific genes, some of these processes have occurred before we knew the structure of the genes, for example, and so the work that began with the discovery of DNA has continued to progress throughout time. Also crucial in advancing our understanding of genes today is the availability of more sophisticated methods, particularly in sequencing technologies, that allow us to identify changes in structures that can be used to deduce the functions of proteins. Indeed, this approach, also known as proteomics, allows us to directly observe patterns of amino acids, and thus to deduce protein interactions.

2.) Understanding How Evolution Works –

In the late 19th and early 20th centuries, one of the greatest challenges faced by evolutionary biologists was to figure out the general laws governing the formation of biological molecules and ultimately the evolution of the species (theory). Several theories arose in parallel to the emergence and subsequent spread of Darwinian ideology across Europe. One of the first of these, which began to gain considerable popularity in the mid-19th and early 20th centuries, is the theory of the evolability and stability of gene structures, or rather their capacity to evolve to fit the needs of the species. During the 1920s and 1930s there was great interest in studying gene functions (since the 1940s we know that the actual structure, i.e., the combination of certain functions) to provide evidence for evolutionary change, and this work was aided by progress in the fields of cellular physiology and genetics. It was during the 1950s and 1960s that the rise of genetic engineering ushered in the beginning of biological analysis and development of genes, with much of the groundwork laid by scientists such as Charles Rice (1936–2005), Francis Crick (1948–74), and Jack Watson (1956–67) who are credited with helping to establish the field of genomics. From the mid-1960s, after the end of World War II, through the 1970s, advances in genetic analysis and cell cytology enabled biologists to examine gene sequences directly and comprehensively to detect and determine gene expression patterns and functions. Genetic analyses focused primarily on looking for changes in gene sequences along with other kinds of mutations to demonstrate the presence of functional differences among genes. The development of cellular techniques to study gene structures allowed scientists to begin to draw connections among genes with similar structures. Because of the increased power of cellular techniques, genome scanning to find sequences that correspond to proteins and, subsequently, to analyze their structure, was made possible, through the introduction of fast, automated DNA-extraction devices that were developed by the 1950s. Such tools also became widely available during this period, and led to a large increase in the number of sequences studied for identification of genes and proteins. This

Conclusion

The growth of computational approaches for identifying genes (or proteins) and of methods for reconstructing protein structures based on such sequences. Both of these methods, genome-scanning and proteomic reconstructions, allowed us to identify a large variety of genes, in addition to the ones listed above and provided key insights into the structure and functions of them, and to reveal mechanisms underlying changes in the genomic, transcription, and RNA environments in the human body, and in viruses and bacteria. Since the 1960s, the development of whole genome sequencing (WGS) technology—based mainly on a method developed by John

Leave a Reply

Your email address will not be published. Required fields are marked *